Answer: 150
Step-by-step explanation:30 an hour
Answer: The first one -4x-3<13
Step-by-step explanation: because they didn't really tell us what happened to the 3 just that the 3 disappeared and the 13 became 16
Make a proportion
81/30 = x/600
600/30 = 20
x/81 = 20
x = 1620
Solution: 1620 calories
Each medal is different and is handed out depending on the outcome of the race/order of the racers, so we're counting the number of permutations. 4 medals are given to 4 runners, so there are

possible ways to do it.
Divide distance with time